How Humans Are Shaping Our Own Evolution

Like other species, we are the products of millions of years of adaptation. Now we're taking matters into our own hands.

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This story appears in the
April 2017 issue of
National Geographic magazine.

When I met the cyborg Neil Harbisson, in Barcelona, he looked like any local hipster, except for the black antenna arching impressively from the back of his skull over his mop of blond hair.

It was December, and Harbisson, 34, was wearing a zippered gray shirt under a black peacoat, with narrow gray pants. Born in Belfast and raised in Spain, he has a rare condition called achromatopsia; he cannot perceive color. His antenna, which ends in a fiber-optic sensor that hovers right above his eyes, has changed that.

Harbisson never felt that living in a black-and-white world was a disability. “I see longer distances. Also I memorize shapes more easily because color doesn’t distract me,” he told me, in his careful, neutral English.

But he was deeply curious about what things looked like in color too. Having trained as a musician, he had the idea in his late teens of trying to discover color through sound. After some low-tech false starts, in his early 20s he found a surgeon (who remains anonymous) who was willing to implant a device, a cybernetic enhancement to his biological self.

The fiber-optic sensor picks up the colors in front of him, and a microchip implanted in his skull converts their frequencies into vibrations on the back of his head. Those become sound frequencies, turning his skull into a sort of third ear. He correctly identified my blazer as blue and, pointing his antenna at his friend Moon Ribas, a cyborg artist and dancer, said her jacket was yellow—it was actually mustard yellow, but as he explained, in Catalonia “we didn’t grow up with mustard.”

When I asked Harbisson how the doctor had attached the device, he cheerfully parted the hair at the back of his head to show me the antenna’s point of entry. The pinkish flesh was pressed down by a rectangular plate with two anchors. A connected implant held the vibrating microchip, and another implant was a Bluetooth communication hub, so friends could send him colors through his smartphone.

The antenna has been a revelation for Harbisson. The world is more exhilarating for him now. Over time, he said, the input has begun to feel neither like sight nor hearing but a sixth sense.

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12,500 Years ago: Evolved to live at high altitudes

Until recently it was thought that our species had stopped evolving far in the past. Our ability to peer inside the human genome has shown that in fact our biology continues to change to suit particular environments. Most of us feel breathless in high mountain air because our lungs must work harder to capture the reduced level of oxygen there. But Andeans have a genetically determined trait that allows their hemoglobin to bind more oxygen. Tibetan and Ethiopian populations independently adapted to their high elevations, showing that natural selection can take us on different paths to reach the same outcome: survival.

The most intriguing part of the antenna, though, is that it gives him an ability the rest of us don’t have. He looked at the lamps on the roof deck and sensed that the infrared lights that activate them were off. He glanced at the planters and could “see” the ultraviolet markings that show where nectar is located at the centers of the flowers. He has not just matched ordinary human skills; he has exceeded them.

He is, then, a first step toward the goal that visionary futurists have always had, an early example of what Ray Kurzweil in his well-known book The Singularity Is Near calls “the vast expansion of human potential.” Harbisson hadn’t particularly meant to jump-start Kurzweil’s dream—his vision of the future is more sylvan than silicon. But since he became the world’s first official cyborg (he persuaded the British government to let him wear the antenna in his passport photo, arguing that it was not an electronic device, but an extension of his brain), he has also become a proselytizer. Ribas soon followed him into what is sometimes called transhumanism by having a seismic monitor in her phone connect to a vibrating magnet buried in her upper arm. She gets real-time reports of earthquakes, allowing her to feel connected to the motions of the Earth and interpret them through dance. “I guess I got jealous,” she says.

“We will transcend all of the limitations of our biology,” Kurzweil promised. “That is what it means to be human—to extend who we are.”

Clearly Harbisson’s antenna is merely a beginning. But are we on the way to redefining how we evolve? Does evolution now mean not just the slow grind of natural selection spreading desirable genes, but also everything that we can do to amplify our powers and the powers of the things we make—a union of genes, culture, and technology? And if so, where is it taking us?

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8,000 Years ago: Adapted to a desert climate

The desert presented an evolutionary challenge for the inhabitants of Sahul, the continent that once united Australia, New Guinea, and Tasmania. After the ancestors of modern Aboriginals made the crossing to Sahul, around 50,000 years ago, they developed adaptations that allowed them to survive below-freezing temperatures at night and days often exceeding 100 degrees Fahrenheit. A genetic mutation in a metabolism-regulating hormone provides this survival advantage, especially for infants, by modulating the excess energy that’s produced when body temperature rises.

Conventional evolution is alive and well in our species. Not long ago we knew the makeup of only a handful of the roughly 20,000 protein-encoding genes in our cells; today we know the function of about 12,000. But genes are only a tiny percentage of the DNA in our genome. More discoveries are certain to come—and quickly. From this trove of genetic information, researchers have already identified dozens of examples of relatively recent evolution. Anatomically modern humans migrated from Africa sometime between 80,000 and 50,000 years ago. Our original genetic inheritance was appropriate for the warm climates where we first evolved from early hominins to humans, from knuckle-walkers to hunters and gatherers. But a lot has happened since that time, as humans have expanded around the world and the demands posed by new challenges have altered our genetic makeup.

Recent, real-life examples of this process abound. Australian Aboriginals living in desert climates have a genetic variant, developed in the past 10,000 years, that allows them to adjust more easily to extreme high temperatures. Prehistorically, most humans, like other mammals, could digest milk only in infancy—we had genes that turned off the production of the milk-digesting enzyme when we were weaned. But around 9,000 years ago, some humans began to herd animals rather than just hunt them. These herders developed genetic alterations that allowed them to continue making the relevant enzyme for their whole lives, a handy adaptation when their livestock were producing a vitamin-rich protein.

In a recent article in the Scientist, John Hawks, a paleoanthropologist at the University of Wisconsin–Madison, wrote how impressed he was at the speed with which the gene was disseminated: “up to 10 percent per generation. Its advantage was enormous, perhaps the strongest known for any recent human trait.”

Similarly, the ancestors of all non-Africans came out of Africa with dark skin. Indeed even 10,000 years ago, according to researchers, European and African skin looked much the same. But over time humans in darker northern climates evolved less heavily pigmented skin, which helped absorb the sun’s ultraviolet rays and synthesize vitamin D more efficiently. The Inuit of Greenland have an adaptation that helps them digest the omega-3 fatty acids in fish far better than the rest of us. An indigenous population near the Argentine town of San Antonio de los Cobres has evolved to be able to drink the high levels of arsenic that have occurred naturally in their groundwater.

Evolution of human traits

Icons depict cultural and biological milestones in human evolution.

Álvaro Valiño

Evolution is relentless; when the chance of survival can be increased, it finds a way to make a change—sometimes several different ways. Some Middle Eastern populations have a genetic variation that’s different from the one northern Europeans have to protect them from lactose intolerance. And there are a half dozen distinct genetic adaptations that protect Africans against malaria (one has the significant drawback of also causing sickle-cell anemia, if the altered form of the gene is inherited from both parents). In the past 50 years researchers have uncovered a variety of adaptations in Andeans, Ethiopians, and Tibetans that allow them to breathe more efficiently at high altitudes. Andean populations retain higher levels of oxygen in their blood. Among Tibetans there is evidence that a gene was introduced through interbreeding with Denisovans, a mysterious branch of the human lineage that died out tens of thousands of years ago. All these adaptations give indigenous people living at high altitudes an advantage over the woozy visitor gasping for oxygen in the mountain air.

Early in origin of species, Charles Darwin comes out fighting: “Natural Selection, as we shall hereafter see, is a power incessantly ready for action, and is immeasurably superior to man’s feeble efforts, as the works of Nature are to those of Art.” The book was published in 1859. Is what was true then still true today? Was it true even in Darwin’s lifetime? Biological evolution may be implacable, and indeed more skillful than the genetic evolution humans can effect with crossbreeding in plants and animals, but how important is it, measured against the adaptations we can devise with our brains? To paraphrase the paleoanthropologist Milford Wolpoff, if you can ride a horse, does it matter if you can run fast?

In our world now, the primary mover for reproductive success—and thus evolutionary change—is culture, and its weaponized cousin, technology. That’s because evolution is no match for the speed and variety of modern life. Despite what evolution has accomplished in the recent past, think of how poorly adapted we are to our computer screens and 24-hour schedules, our salty bags of corn chips and pathogen-depleted environments. Why are our internal clocks so rigid? Why can’t our seemingly useless appendix, which may have once helped us digest grass, shift to break down sugars instead? If human genetics were a tech company, it would have gone bankrupt when steam power came along. Its business plan calls for a trait to appear by chance and then spread by sexual reproduction.

This works nimbly in mice, which can produce a new litter in three weeks, but humans go about things more slowly, producing a new generation only every 25 to 35 years or so. At this rate, it can take thousands of years for an advantageous trait to be spread throughout a population. Given genetic evolution’s cumbersome protocols, it’s no surprise technology has superseded it. Technology now does much of the same work and does it far faster, bolstering our physical skills, deepening our intellectual range, and allowing us to expand into new and more challenging environments.

“People get hung up on Darwin and DNA,” says George Church, a molecular engineer with a joint appointment at Harvard and MIT. “But most of the selection today is occurring in culture and language, computers and clothing. In the old days, in the DNA days, if you had a pretty cool mutation, it might spread in the human race in a hundred thousand years. Today if you have a new cell phone or transformative manufacturing process, it could spread in a week.”

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Present day: Technology versus natural selection

We big-brained humans have done much to neutralizethe power of natural selection. With our tools, medicine, and other cultural innovations, we have started a potentially deadly race—one we could lose to a highly evolved superbug. Given the speed with which we can spread disease around the globe, “we are in a new pandemic era and must take action now to stop it,” says Kevin Olival, a disease ecologist at EcoHealth Alliance. Shifts brought about by habitat destruction and climate change are also bringing more people into contact with pathogens previously isolated from human hosts.

To be sure, the picture is more complicated. As the cyberpunk writer William Gibson has pointed out: “The future is already here. It’s just not evenly distributed yet.” Some of us live in Church’s world of jet travel and intersociety marriage, of molecular medicine and gene therapy, and seem to be heading toward a time when our original genetic makeup is simply a draft to be corrected. But outside the most developed parts of the world, DNA is still often destiny.

Not all trends are irreversible, however. There are scenarios under which natural selection would return to center stage for the rest of us too. If there were a global disease outbreak, for instance, along the lines of the great influenza pandemic of 1918, those with a resistance to the pathogen (because of a robust immune system or protective bacteria that could render such a pathogen innocuous) would have a huge evolutionary advantage, and their genes would carry forward into subsequent generations while the rest of us died out.

We have medicines today to combat many infectious diseases, but virulent bacteria have recently evolved that do not respond to antibiotics. Jet travel can send an infectious agent around the world in a day or two. Climate change might prevent cold temperatures from killing off whatever animal carried it, as winter may have once killed the fleas that harbored the plague.

Elodie Ghedin, a microbiologist at New York University, says, “I don’t know why people aren’t more scared.” She and I discussed the example of AIDS, which has killed 35 million people worldwide, a death toll roughly equal to that of the 1918 pandemic. It turns out that a small percentage of people—no more than one percent—have a mutation of the gene that alters the behavior of a cellular protein that HIV, the virus that causes AIDS, must latch on to, making it nearly impossible for them to become infected. If you live in New York City’s Greenwich Village, with access to the best antiviral drugs, this may not decide if you live or die. But if you are HIV-positive in rural Africa, it very well might.

There are many more scenarios by which genes could return to center stage in the human drama. Chris Impey, a professor of astronomy at the University of Arizona and an expert on space travel, foresees a permanent Martian settlement within our grandchildren’s lifetimes, stocked by the 100 or 150 people necessary to make a genetically viable community. A first, smaller wave of settlement he regards as even closer at hand: “When Elon Musk is glue-sniffing, he might say 10 to 15 years,” Impey says, “but 30 to 40 doesn’t seem that radical.” Once the settlement is established, he adds, “you’re going to accelerate natural evolutionary processes. You’re going to have a very artificial and physically difficult environment that’s going to shape the framework of the travelers or colonists in a fairly aggressive way.” The optimal Earthling turned Martian, he says, would be long and slender, because gravity on the red planet has about one-third the force of Earth’s. Over generations, eyelashes and body hair might fade away in an environment where people never come directly into contact with dust. Impey predicts—assuming that the Martian humans did not interbreed with terrestrial ones—significant biochemical changes in “tens of generations, physical changes in hundreds of generations.”

One human trait with a strong genetic component continues to increase in value, even more so as technology grows more dominant. The universal ambition of humanity remains greater intelligence. No other attribute is so desirable; no other so useful, so varied in its applications, here and on any world we can imagine. It was indispensable to our forebears in Africa and will come in handy for our descendants on the planet orbiting the star Proxima Centauri, should we ever get there. Over hundreds of thousands of years, our genes have evolved to devote more and more resources to our brains, but the truth is, we can never be smart enough.

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Present day and near future: Do-it-yourself evolution

Pairing in vitro fertilization with another process allows us to test embryos for mutations that could lead to serious medical conditions. Now we’re developing powerful new gene-editing tools that could bring about human-directed evolution. Most research has been on other organisms—for instance, attempting to change a mosquito genome so that the insect cannot transmit Zika or malaria. We could harness the same techniques to “design” our babies—simply to choose a preferred hair or eye color. But should we? “There’s definitely a dark side,” says bioethicist Linda MacDonald Glenn, “but I do think humanity-plus is inevitable. We are, by our nature, tinkerers.”

Unlike our forebears, we may soon not need to wait for evolution to fix the problem. In 2013 Nick Bostrom and Carl Shulman, two researchers at the Future of Humanity Institute, at Oxford University, set out to investigate the social impact of enhancing intelligence, in a paper for Global Policy. They focused on embryo selection via in vitro fertilization. With IVF, parents can choose which embryo to implant. By their calculations, choosing the “most intelligent embryo” out of any given 10 would increase a baby’s IQ roughly 11.5 points above chance. If a woman were willing to undergo more intensive hormone treatments to produce eggs faster—“expensive and burdensome,” as the study notes with understatement—the value could grow.

The real benefit, though, would be in the compound gain to the recipient’s descendants: After 10 generations, according to Shulman, a descendant might enjoy an IQ as much as 115 points higher than his or her great-great-great-great-great-great-great-great-grandmother’s. As he pointed out to me, such a benefit is built on extremely optimistic assumptions, but at the least the average recipient of this genetic massaging would have the intelligence equal to a genius today. Using embryonic stem cells, which could be converted into sperm or ova in just six months, the paper notes, might yield far faster results. Who wants to wait two centuries to be the scion of a race of geniuses? Shulman also mentioned that the paper omitted one obvious fact: “In 10 generations there will likely be computer programs that outperform even the most enhanced human across the board.”

There’s a more immediate objection to this scenario, though: We don’t yet know enough about the genetic basis for intelligence to select for it. One embryo doesn’t do advanced calculus while another is stuck on whole numbers. Acknowledging the problem, the authors claim that the ability to select for “modest cognitive enhancement” may be only five to 10 years off.

At first glance this would seem improbable. The genetic basis of intelligence is very complex. Intelligence has multiple components, and even individual aspects—computational ability, spatial awareness, analytic reasoning, not to mention empathy—are clearly multigenetic, and all are influenced by environmental factors as well. Stephen Hsu, vice president for research at Michigan State University, who co-founded the Cognitive Genomics Lab at BGI (formerly Beijing Genomics Institute), estimated in a 2014 article that there are roughly 10,000 genetic variants likely to have an influence on intelligence. That may seem intimidating, but he sees the ability to handle that many variants as nearly here—“in the next 10 years,” he writes—and others don’t think you’d need to know all the genes involved to start selecting smarter embryos. “The question isn’t how much we know or don’t know,” Church says. “It’s how much we need to know to make an impact. How much did we need to know about smallpox to make a vaccine?”

If Church and Hsu are right, soon the only thing holding us back will be ourselves. Perhaps we don’t want to practice eugenics on our own natural genomes. Yet will we pause? If so, for how long? A new technology called CRISPR-Cas9 has emerged, developed in part in Church’s lab, that will test the limitations on human curiosity. First tried out in 2013, CRISPR is a procedure to snip out a section of DNA sequence from a gene and put a different one in, quickly and accurately. What used to take researchers years now takes a fraction of the time. (See “DNA Revolution,” in the August 2016 issue of National Geographic.)

No technology remotely as powerful has existed before for the manipulation of the human genome. Compare CRISPR and IVF. With IVF you select the embryo you want from the ones nature has provided, but what if none of the embryos in a given set is, for instance, unusually intelligent? Reproduction is a crapshoot. A story, likely apocryphal, illustrates the point: When the dancer Isadora Duncan suggested to the playwright George Bernard Shaw that they have a baby together so it would have her looks and his brains, he is said to have retorted: “But what if it had your brains and my looks?” CRISPR would eliminate that risk. If IVF is ordering off a menu, CRISPR is cooking. In fact, with CRISPR, researchers can insert a new genetic trait directly into the egg or sperm, thus producing, say, not just a single child with Shaw’s intelligence and Duncan’s looks but an endless race of them.

So far many experiments using CRISPR have been done on animals. Church’s lab was able to use the procedure to reengineer pig embryos to make their organs safer for transplant into humans. A colleague of Church’s, Kevin Esvelt at the MIT Media Lab, is working to alter the mouse genome so the animal can no longer host the bacterium that causes Lyme disease. A third researcher, Anthony James of the University of California, Irvine, has inserted genes in the Anopheles mosquito that prevent it from carrying the malaria parasite.

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Near future: Science fiction becomes reality

More than 50 years ago two scientists coined the word “cyborg” for an imaginary organism—part human, part machine. It seemed science fiction, but today around 20,000 people have implants that can unlock doors. Neil Harbisson, who can perceive colors only by transforming them into sounds he can hear through an antenna implanted in his head, sees a future vastly improved by widening our senses with such technology. “Night vision,” he says, “would give us the ability to adapt to the environment: design ourselves instead of the planet. Designing the planet is harming it.”

Around the same time, however, researchers in China surprised everyone by announcing that they had used CRISPR in nonviable human embryos to try to fix the genetic defect that causes beta-thalassemia, a potentially fatal blood disorder. Their attempt failed, but moved them closer to finding a way to fix the defect. Meanwhile there is an international moratorium on all therapies for making heritable changes in human genes until they are proved safe and effective. CRISPR is no exception.

Will such a halt last? No one I spoke to seemed to think so. Some pointed to the history of IVF as a precedent. It was first touted as a medical procedure for otherwise infertile couples. Soon its potential to eradicate devastating genetic diseases was clear. Families with mutations that caused Huntington’s or Tay-Sachs diseases used the technique to choose disease-free embryos for the mother to carry to term. Not only was the child-to-be spared much misery, but so were his or her potential offspring. Even if this was playing God in the nursery, it still seemed reasonable to many people. “For this sort of technology to be banned or not used,” notes Linda MacDonald Glenn, a bioethicist at California State University, Monterey Bay, “is to suggest that evolution has been benign. That it somehow has been a positive. Oh Lord, it has not been! When you think of the pain and suffering that has come from so many mistakes, it boggles the mind.”

As IVF became more familiar, its accepted purpose spread from preventing disease to include sex selection—most notably in Asia, where the desire for sons has been overwhelming, but also in Europe and America, where parents talk about the virtues of “family balancing.” Officially, that’s as far as the trend toward nonmedical uses has gone. But we are the species that never knows when to stop. “I have had more than one IVF specialist tell me that they can screen for other desirable traits, such as desired eye and hair color,” Glenn told me. “It is not advertised, just via word of mouth.” In other words, a green-eyed, blond child, if that’s your taste, could already be yours for the asking.

CRISPR is a vastly more powerful technology than IVF, with a far greater risk of abuse, including the temptation to try to engineer some sort of genetically perfect race. One of its discoverers, Jennifer Doudna, a professor of chemistry and molecular biology at the University of California, Berkeley, recounted to an interviewer a dream she’d had in which Adolf Hitler came to learn the technique from her, wearing a pig’s face. She emailed me recently to say she still hoped the moratorium would last. It would, she wrote, “give our society time to research, understand, and discuss the consequences, both intended and unintended, of changing our own genome.”

On the flip side, the potential benefits of applying CRISPR to humans are undeniable. Glenn hopes at least for “thoughtful discussions” first on how the technique will be used. “What becomes the new norm as we try to improve ourselves?” she asks. “Who sets the bar, and what does enhancement mean? You might enhance people to make them smarter, but does smarter equal better or happier? Should we be enhancing morality? And what does that mean?”

Many other scientists don’t think everyone will wait to find out; as soon as CRISPR is shown to be safe, ethical questions will recede, just as they did with IVF. Church thinks this still misses the point: The floodgates are already open to genetic reengineering—CRISPR’s but one more drop in the river. He notes that there are already 2,300 gene therapy trials under way. Last year the CEO of a company called BioViva claimed to have successfully reversed some of the effects of aging in her own body with injections from a gene therapy her company devised. “Certainly,” Church notes, “aging reversal is just as augmentative as anything else we were talking about.” Several gene therapy trials for Alzheimer’s are also in progress. These won’t likely produce any objections, because they are to treat a devastating medical condition, but as Church points out, “whatever drugs work to prevent Alzheimer’s will probably also work for cognitive enhancement, and they will work in adults almost by definition.” In February 2016 the boundary crumbled a bit more when the United Kingdom’s independent fertility regulator gave a research team permission to use CRISPR to explore the mechanisms of miscarriage with human embryos (all embryos used in the experiments will ultimately be destroyed—no pregnancies will result).

Church can’t wait for the next chapter. “DNA was left in the dust by cultural evolution,” he says, “but now it’s catching up.”

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Distant future: Can humans adapt to the red planet?

Large-scale evolutionary divergence from the human norm requires a population to be isolated for thousands of years—unlikely on Earth. But it’s possible we could have a small settlement on Mars before a half century passes. Then would come a larger community—100 to 150 people, with members of reproductive age to sustain and increase its numbers. Could we evolve into ideal Martians? Space travel expert Chris Impey, a professor of astronomy at the University of Arizona, foresees a colony of Martians among whom scientists could accelerate natural evolutionary processes. Bodies would become tall and thin in response to an atmosphere with less than 40 percent of Earth’s gravity, and hairless in a controlled environment where there is no dust.

Our bodies, our brains, and the machines around us may all one day merge, as Kurzweil predicts, into a single massive communal intelligence. But if there’s one thing natural evolution has shown, it’s that there are many paths to the same goal. We are the animal that tinkers ceaselessly with our own limitations. The evolution of evolution travels multiple parallel roads. Whatever marvelous skills CRISPR might provide us 10 years from now many people want or need now. They follow Neil Harbisson’s example. Instead of going out and conquering technology, they bring it within themselves.

Medicine is always the leading edge in these applications, because using technology to make someone well simplifies complicated moral questions. A hundred thousand Parkinson’s disease sufferers worldwide have implants—so-called brain pacemakers—to control symptoms of their malady. Artificial retinas for some types of blindness and cochlear implants for hearing loss are common. Defense Department money, through the military’s research arm, the Defense Advanced Research Projects Agency (DARPA), funds much of this development. Using such funding, a lab at the University of Southern California’s Center for Neural Engineering is testing chip implants in the brain to recover lost memories. The protocol might one day be applied to Alzheimer’s patients and those who have suffered a stroke or traumatic brain injury. Last year, at the University of Pittsburgh, a subject was able to transmit electrical impulses from his brain, via a computer, to control a robotic arm and even sense what its fingers were touching. That connecting the human brain to a machine would produce a matchless fighter has not been lost on DARPA. “Everything there is dual purpose,” says Annie Jacobsen, whose book The Pentagon’s Brain chronicles such efforts. “You have to remember DARPA’s job isn’t to help people. It’s to create ‘vast weapon systems of the future.’ ”

Human enhancements needn’t confer superhuman powers. Hundreds of people have radio-frequency identification (RFID) devices embedded in their bodies that allow them to unlock their doors or log on to their computers without touching anything. One company, Dangerous Things, claims to have sold 10,500 RFID chips, as well as do-it-yourself kits to install them under the skin. The people who buy them call themselves body hackers or grinders.

Kevin Warwick, an emeritus professor of engineering at Reading and Coventry Universities, in England, was the first to have an RFID device implanted in his body, back in 1998. He told me the decision had been a natural emanation of working in a building with computerized locks and automatic sensors for temperature and light: He wanted to be as smart as the structure that housed him. “Being a human was OK,” Warwick told a British newspaper in 2002. “I even enjoyed some of it. But being a cyborg has a lot more to offer.” Another grinder had an earbud implanted in his ear. He wants to implant a vibrator beneath his pubic bone and connect it via the web to others with similar implants.

It’s easy to caricature such things. The practitioners reminded me of the first men who tried to fly, with long arm paddles fringed with feathers. But it was when I asked Harbisson to show me where his antenna entered his skull that I realized something else. I wasn’t sure whether the question was appropriate. In Philip K. Dick’s novel Do Androids Dream of Electric Sheep? (the book that became the movie Blade Runner) it’s considered rude to ask about the mechanisms powering an android. “Nothing could be more impolite,” the narrator opines. But Harbisson was eager to show me how his antenna worked. He reminded me of how happily people show off their new smartphones or fitness trackers. I began to wonder what the difference really was between Harbisson and me—or any of us.

Nielsen reported in 2015 that the average adult over 18 spent roughly 10 hours a day looking at a screen. (By comparison, we spend 17 minutes a day exercising.) I still remember the home phone number of my best friend from childhood, but not the numbers of any of my good friends now. (This is true of seven of 10 people, according to a study published in Britain.) Seven out of 10 Americans take a prescription drug; of these, one in four women in their 40s or 50s takes an antidepressant, though studies show that for some of them anything from therapy to a short walk in the woods can do as much good. Virtual reality headsets are one of the hottest selling gamer toys. Our cars are our feet, our calculators are our minds, and Google is our memory. Our lives now are only partly biological, with no clear split between the organic and the technological, the carbon and the silicon. We may not know yet where we’re going, but we’ve already left where we’ve been.

Like any other species, we are the product of millions of years of evolution. Now we’re taking matters into our own hands.

D. T. Max is a
New Yorker staff writer and author of
The Family That Couldn’t Sleep: A Medical Mystery.Owen Freeman is an illustrator based in Los Angeles. His artwork covers science, history, entertainment, and current events. Artist
Álvaro Valiño,
whose
work has appeared in various National Geographic publications, created the icons featured in this story.